SunshinePHP Developer Conference 2015

gzdeflate

(PHP 4 >= 4.0.4, PHP 5)

gzdeflateComprime una cadena

Descripción

string gzdeflate ( string $data [, int $level = -1 [, int $encoding = ZLIB_ENCODING_RAW ]] )

Esta función comprime la cadena dada utilizando el formato de datos DEFLATE.

Para más detalles sobre el algoritmo de compresión DEFLATE ver el documento "» DEFLATE Compressed Data Format Specification version 1.3" (RFC 1951).

Parámetros

data

Los datos a comprimir.

level

El nivel de compresión. Se puede dar desde 0 para ninguna compresión hasta 9 para máxima compresión. Si no se especifica, se utilizará el nivel de compresión por defecto de la librería zlib.

encoding

Una de las constantes ZLIB_ENCODING_*.

Valores devueltos

La cadena comprimida o FALSE si ocurre un error.

Ejemplos

Ejemplo #1 Ejemplo de gzdeflate()

<?php
$compressed 
gzdeflate('Compress me'9);
echo 
$compressed;
?>

Historial de cambios

Versión Descripción
5.4.0 Se añadió el parámetro encoding.

Ver también

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User Contributed Notes 6 notes

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9
giunta dot gaetano at sea-aeroportimilano dot it
8 years ago
Take care that that "PHP deflate" != "HTTP deflate".

The deflate encoding used in HTTP is actually zlib encoded.

This is what PHP functions return:
gzencode() == gzip
gzcompress() == zlib (aka. HTTP deflate)
gzdeflate()  == *raw* deflate encoding
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2
anonymous at php dot net
5 years ago
gzcompress produces longer data because it embeds information about the encoding onto the string. If you are compressing data that will only ever be handled on one machine, then you don't need to worry about which of these functions you use. However, if you are passing data compressed with these functions to a different machine you should use gzcompress.
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1
robin
4 years ago
running 50000 repetitions on various content, i found that gzdeflate() and gzcompress() both performed equally fast regardless content and compression level, but gzinflate() was always about twice as fast as gzuncompress().
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0
stockton at wowway dot com
1 year ago
After some searching and experimentation I found that the output from this function cannot be 'inflated' with the objective c 'zlibInflate' wrapper for 'zlib' that is available at http://cocoadev.com/wiki/NSDataCategory but the output from gzcompress() can be. Thank you "anonymous at php dot net" and "tomas at slax dot org" for the clues. I hope this saves someone else the searching.
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0
tomas at slax dot org
6 years ago
gzcompress() is the same like gzdefflate(), it produces identical data and its speed is the same as well. The only difference is that gzcompress produces 6 bytes bigger result (2 extra bytes at the beginning and 4 extra bytes at the end).
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0
denis dot noessler at red-at dot de
11 years ago
if you have compressed data which is greater than 2 MB (system dependent), you will receive a buffer error by calling the function gzinflate().
be sure to to compress your data by a lower compression level, like 1.
i.e.: gzdeflate($sData, 1);
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